Organization definition information M31 is stored in an organization definition information storage unit 31, contents M33 to be provided to a user is stored in a contents storage unit 33 and filter definition information M22 which is sent from a filter definition information generation unit 22 is stored in a filter definition information storage unit 32. A filtering execution unit 23 obtains information M10c on the contents, in which necessary information is stored, from the user, obtains filter definition information M32 on the contents, specified by the information M10c, from the filter definition information storage unit 32, obtains user's organization definition information M31, specified by filter definition information M32, from an organization definition information storage unit 31, builds a filter, and executes filtering to the contents M33.